To ask for more time, you can file paper Form 4868, “Application for Automatic Extension of Time to File U.S. Individual Income Tax Return.” It’s faster if you e-file your request through your own tax preparation software or a hired tax preparer. The IRS will send you a message of receipt if you file this way; paper application forms will not be acknowledged.

When you seek the extension, you should have an idea of whether you’re going to owe money and how much. Do everything you can to pay the full amount when you file for the extension — otherwise you’ll face interest and penalties that could raise your bill by 25 percent.

If you file the extension request on paper, you can attach a check or money order. If you file electronically, you can pay by authorizing a funds withdrawal from a checking or savings account. You can also pay by credit card, though your bill will be a few percentage points higher to offset the credit card company’s commission.

If you’ve completed your return but you owe the IRS money you don’t have, an extension won’t give you time to scrounge it up. In this case, it may be better to file your return by the deadline, pay what you can and apply for a “payment agreement” that will let you string out the rest of what you owe.

Go to the IRS website and click on “Apply for an Online Agreement” on the left side of the page under “Online Services.”

Payments made after the deadline are still subject to interest and penalties.

For more information on all of these options, visit the IRS website. You can talk it over with an IRS employee on the phone by calling 1-800-TAX-1040.